Structural assessment of Mount Etna volcano from Permanent Scatterers analysis

Abstract

[1] A study of the deformation pattern of Mount Etna volcano based on the results from the Permanent Scatterers (PS) technique is reported. Ground motion data provided by the interferometric synthetic aperture radar (InSAR) PS technique from 1995 to 2000 are compared and validated by GPS data. An analysis of the ascending and descending line of sight (LOS) components of ground velocities has yielded detailed ground deformation maps and cross sections. This analysis allows detection and constraint of discontinuities in the surface velocity field. LOS velocities have then been combined to calculate the vertical and horizontal (E-W) ground velocities. A wide inflation of the edifice has been detected on the western and northern flanks (over an area of about 350 km 2 ). A seaward motion of the eastern and southern flanks has also been measured. PS data allows the geometry and kinematics of the several blocks composing the unstable flanks to be defined even in the highly urbanized areas, and their displacement rates have been measured with millimeter precision. This analysis reveals the extension of some features beyond their field evidences and defines new important features. The results of this work depict a new comprehensive kinematic model of the volcano highlighting the gravitational reorganization of the unbuttressed volcanic pile on its slippery clay basement on the southern flank, but an additional drag force due to a strong subsidence of the continental margin facing the Etna volcano is necessary to explain the PS velocity field observed on the eastern flank.Components: 10,900 words, 6 figures.

The unrest of the San Miguel volcano (El Salvador, Central America): installation of the monitoring network and observed volcano-tectonic ground deformation

“…A different sensitivity of different sectors of a volcano to the ground deformation has been observed also, for example, at Mt. Etna (Bonforte et al, , 2011 and is related to the volcanotectonic setting that allows different sides of the edifice to respond differently to different dynamics. A continuous deflation of the volcano is also compatible with the geochemical observations that evidenced a higher degassing (with respect to the background level before the eruption, Granieri et al, 2015) during the whole investigated period.…”

Semi-automated extraction of Deviation Indexes (DI) from satellite Persistent Scatterers time series: tests on sedimentary volcanism and tectonically-induced motions

“…Wright et al, 2001;Bürgmann et al, 2006), and volcanic deformations (e.g. Tizzani et al, 2007;Bonforte et al, 2011). Similarly, local scale applications to structural and geological instability affecting urban areas, archaeological and cultural heritage sites are also consolidating gradually (e.g.…”

Modeling ground deformation associated with the destructive earthquakes occurring on Mt. Etna's southeastern flank in 1984

“…The TFS plays a key role in the local tectonics accommodating the ESE seaward sliding (Azzaro et al, 2013a), the ME and MF motions and the edifice inflation/deflation episodes (Trasatti et al, 2009); this fault system divides the sliding sector into several blocks (Solaro et al, 2010;Bonforte et al, 2011) characterized by homogeneous kinematics with relative motion measured by permanent scatterers along the faults of about 3-5 mm yr −1 in a "quiet" period such as 1995-2000 .…”

“…The Mt. Etna GPS network has enabled us to determine how the entire eastern flank is affected by an ESE-ward motion, at a mean rate of about 1-3 cm yr −1 (e.g., Bonforte et al, 2011;Gambino et al, 2011). Moreover, starting from 1980, the sliding area underwent two marked acceleration phases in October 1984-1986and in October 2002, as described in Alparone et al (2013c).…”